In modern day farming operations, particularly in grain farming operations, it is necessary to apply a number of agricultural chemicals to the crops at various times during the growing season. Such agricultural chemicals include fertilizers, pesticides, herbicides and the like. Since these chemicals are normally in liquid form or applied using a carrier liquid, spraying is the most convenient and commonplace mode of application.
Various apparatus are known in the agricultural arts for the spray type application of liquid type chemicals. One type of such apparatus is used solely for spraying and comprises a wheeled vehicle supporting a tank containing the agricultural chemical and one or more spray heads communicating with the interior of the tank. The vehicle is adapted to be towed behind a tractor or the like when spraying operations are conducted. Examples of apparatus of this type are shown in U.S. Pat. No. 1,471,256 to Frederick; U.S. Pat. No. 1,561,645 to Howard and U.S. Pat. No. 3,515,349 to Mecklin et al.
Another type of apparatus for applying agricultural chemicals comprises attachments for conventional farming equipment which enables spraying to be accomplished while other farm operations are being conducted. For example, devices are known which attach to a conventional planter, disc or the like to enable the application of chemicals during planting or discing operations. Devices of this type are shown and described in U.S. Pat. No. 3,632,043 to Kirschmann and in U.S. Pat. No. 3,874,593 to Wilt.
Since agricultural spray apparatus of both types are normally used to apply a variety of chemicals to different crops, it is important that the apparatus be capable of adjustment so as to vary the spray applications height, spray angle, row spacing and the like to provide the optimum spraying conditions for that particular chemical and the particular crop at its stage of growth. While most conventional apparatus have some degree of adjustability for spraying conditions, the adjustment is often times difficult and optimum spray position cannot always be achieved due to inherent limits in the adjustablity.